Surgical clamp pads having surface overlay

ABSTRACT

A replaceable pad or insert for attachment to the jaw of a jaw-type occlusion device. The insert includes a compliant cushion and a flexible non-compliant surface overlay secured to the cushion surface. The overlay can be metal or plastic and can further include notches along the overlay sides to increase flexibility of the overlay.

BACKGROUND OF THE INVENTION

[0001] The present invention relates generally to surgical instrumentsfor occluding a vessel or other body conduit, and more particularly, toreplaceable pads or inserts for attachment to jaw-type occlusiondevices.

[0002] Instruments for occluding blood vessels and other body conduitsare well known. Conventional surgical clamps or clips are often made ofmetal, such as stainless steel, or other similarly rigid materials. Suchsurgical clamps are favored for a number of reasons. They can bemanufactured to have a low profile, and the overall structural rigidityof the clamps together with the non-deflectable and non-deformablegripping surfaces provides a clamp having excellent gripping properties.Gripping can be further improved by providing surface irregularities tothe gripping surfaces, such as scoring the surface or otherwiseincluding serrations, teeth, or other raised protrusions. As one suchexample, U.S. Pat. No. 3,515,139 to Mallina discloses surgical forcepswith hard plastic inserts having spherical protuberances andcomplementary grooves or spherical cavities. A disadvantage, however, ofsuch clamps is that the hard surfaces and rigidity of the clamps cancause trauma to the clamped vessel at the clamping site

[0003] As a result, a number of atraumatic instruments have beendeveloped for reducing trauma to a vessel during occlusion. Inparticular, conventional surgical clamps and clips have been adapted toinclude jaw surfaces containing resilient members or pads. These deviceslikewise have their disadvantages. For example, these devices are proneto slipping off of the clamped vessel. This can be especiallyproblematic in situations where, due to obstructions, a vessel has beenclamped with only the distal tips of the clamp jaws. In such situations,the vessel can be especially prone to slipping in the direction of thedistal tips. Also, due to the deformability of such pads or members,such pads or members are prone to slipping laterally on a clampedvessel, resulting in a “scissor-like” effect where the jaws can twistoff-line. In such a situation, effective clamping of the vessel iscompromised.

[0004] Other attempts have thus been made to atraumatically occlude avessel in a more secure fashion. U.S. Pat. No. 3,746,002 to Hallerdiscloses a vascular clamp with resilient gripping members on the jawsthat are formed of a resilient material having a plurality of hard pinmembers embedded therein. The pin members are of a length such that whena vessel is clamped between the gripping members, the resilient materialdeflects to accommodate the vessel, exposing the pin members whichgrippingly engage the outer layer of the vessel, thus securing thevessel to the gripping member. While the Haller device is less traumaticto a vessel than other occlusion devices, it nevertheless has thedisadvantage of traumatizing the outer layer of the vessel.

[0005] U.S. Pat. No. 3,503,397 to Fogarty discloses surgical clamps withjaw inserts having hard plastic teeth along the edges of the insert witha softer component along the interior of the insert. The hard teeth ofthis device serve to resist movement of a clamped vessel laterally ofthe jaw, but again do so at increased risk of trauma to the vessel.Still further attempts have been made to atraumatically occlude avessel, such as those disclosed in PCT Publication WO 99/11179

[0006] There thus remains a need for a surgical clamp whichatraumatically occludes vessels with improved gripping capabilitieswhile simultaneously avoiding the disadvantages previously associatedwith existing surgical clamps or occlusion devices.

SUMMARY OF THE INVENTION

[0007] The present invention meets these and other needs and providesfor replaceable surgical clamp pads or inserts having a compliantcushion and a flexible non-compliant overlay secured onto the cushionsurface for engagement with a vessel or other body tissue. Variousattaching structures can be provided on the cushion for securing the pador insert onto the clamp jaw.

[0008] In one aspect of the invention, the overlay can entirely coverthe cushion surface. In another aspect of the invention, a series ofnotches can be provided along the sides of the overlay to increase theflexibility of the overlay. The combination of surface overlay andunderlying compliant cushion results in an insert that as a wholedeflects to accommodate a clamped vessel while providing surfaceclamping characteristics associated with conventional clamps. Thedeflection of the insert, which is a function of the underlyingcompliant cushion, reduces trauma to the clamped vessel. At the sametime, the non-compliant overlay provides a non-deformable clampingsurface similar to that provided by conventional rigid metal or hardplastic clamps, thereby providing gripping characteristics approximatingconventional rigid metal or hard plastic clamps.

[0009] In one embodiment of the invention, the overlay can be formed ofa metal, such as stainless steel. In another embodiment of theinvention, the overlay can be formed of a thermoplastic.

[0010] In another aspect of the invention, the overlay itself can beprovided with a textured surface having surface irregularities toprovide for increased traction between the overlay and the engagedvessel or body tissue. In one such embodiment the overlay can includeprotrusions extending from the overlay surface. In another suchembodiment, such protrusions can be in the form of a plurality ofcolumns extending from the overlay in a direction generallyperpendicular to the cushion surface. In yet another such embodiment,the surface overlay can include a multiplicity of perforations.

[0011] Methods of manufacturing the replaceable pad or inserts of thepresent invention are also provided.

[0012] These and other features of the invention will be even betterunderstood by reference to the accompanying drawings and description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a perspective view of an insert according to a firstembodiment of the invention, showing a compliant cushion with a surfaceoverlay;

[0014]FIG. 2 is a side view of the insert of FIG. 1;

[0015]FIG. 3 is a cross-section view of the insert of FIG. 1 taken on aplane designated by line 3-3 of FIG. 2;

[0016]FIG. 4 is a side view of jaw-type surgical clamp, with partsbroken away, having the inserts of FIG. 1 installed on the jaws andengaged with a vessel;

[0017]FIG. 5A is a perspective view of an insert according to a secondembodiment of the invention;

[0018]FIG. 5B is a perspective view of a modified version of the insertof FIG. 5A;

[0019]FIG. 5C is a perspective view of yet another modified version ofthe insert of FIG. 5A;

[0020]FIG. 6 is a side view of the insert of FIG. 5A;

[0021]FIG. 7A is a cross-section view of the insert of FIG. 5A taken ona plane designated by line 7A-7A of FIG. 6;

[0022]FIG. 7B is a cross-section view of the insert of FIG. 5B taken ona plane designated by line 7B-7B of FIG. 5B;

[0023]FIG. 8 is a perspective view of an insert according to a thirdembodiment of the invention;

[0024]FIG. 9 is a side view of the insert of FIG. 8;

[0025]FIG. 10 is a cross-section view of the insert of FIG. 8 taken on aplane designated by line 10-10 of FIG. 9;

[0026]FIG. 11 is an expanded perspective view of the surface overlay ofthe insert of FIG. 8, with parts broken away;

[0027]FIG. 12 is a perspective view of an insert according to a fourthembodiment of the invention;

[0028]FIG. 13 is a side view of the insert of FIG. 12; and

[0029]FIG. 14 is a cross-section view of the insert of FIG. 12 taken ona plane designated by line 14-14 of FIG. 13.

DETAILED DESCRIPTION OF THE INVENTION

[0030] FIGS. 1-3 depict a first embodiment of a replaceable surgicalclamp pad or insert according to the invention. Insert 10 includescushion 14 having surface overlay 16 that extends over the cushionsurface. The cushion itself is secured to attachment member 12 forattaching the insert to the jaw of a jaw-type occlusion device.

[0031] Cushion 14 can be formed of a variety of materials known in theart that are compliant and that will therefore provide a cushioningeffect to a clamped vessel. Most suitable are elastomeric materials thatare resiliently deflectable. Such elastomeric materials include, but arenot limited to, natural rubber, neoprene, urethane, ethyl vinyl acetatefoam, or silicone or silicone foam. It is desirable that the material bea thermoplastic elastomer suitable for injection molding and having a20A-40A shore durometer rating. Such thermoplastic elastomers includepolyurethane, and thermoplastic elastomers sold under the tradenameKRATON™ and DYNAFLEX™ (Shell Chemicals Ltd.). The cushions of theinvention can be formed in a variety of sizes and shapes. In general thecushions will conform to, or be conformable to, the jaw shape of thedesired occlusion device.

[0032] Cushion 14 is secured to attachment member 12 at the surface ofthe cushion opposite surface overlay 16. The attachment member providesa rigid backing for the cushion as well as means for attachment of thecushion to the jaw of a clamp. Attachment member 12 can be made of ahard plastic, such as polycarbonate, or of metal. Means for attachingthe attachment member to the jaw comprise a pair of protrusions 11, thatcan be detachably coupled to recesses on the jaw (not shown). Otherconventional means of attachment may also be employed.

[0033] Alternatively, the cushion can be directly secured to a clamp jawby means described in copending U.S. application Ser. Nos. 09/336,131,09/491,237 and 09/594,291, filed Jun. 18, 1999, Jan. 25, 2000 and Jun.15, 2000, respectively, each commonly owned by the assignee of thepresent application and incorporated herein in their entireties. Onesuch means is depicted in the embodiment of FIGS. 5A, 6 and 7A. Insert20 a includes flexible elongate attachment member 22, which isconfigured for receipt in an elongate cavity or channel that extendslongitudinally of a clamp jaw (not shown). The attachment member 22includes a securing portion configured to extend through the jaw channelor cavity, thereby securing the cushion to the jaw through aninterference fit with the jaw channel or cavity. Such attachment memberscan be formed of a plastic that is flexible but generally stiffer andless deflectable than the cushion material, such as nylon orpolypropylene. Alternatively, attachment member 22′ can be integrallyformed with cushion 24, as show in insert 20 b of FIGS. 5B and 7B. Thesedesigns are especially advantageous in that the resultant inserts canaccommodate a variety of jaw shapes and configurations, including curvedjaws.

[0034] Surface overlay 16 is formed of a flexible, non-compliantmaterial. That is, the material must be flexible and capable of bendingunder an applied load, but at the same time should not deform under suchload. A variety of materials known in the art are suitable for use,including metals and relatively hard plastics. Suitable metals include,for example, stainless steel of sufficient thinness to flex or bendunder a clamping load, preferably between 0.0002 to 0.004 inches thick.Suitable plastics include, for example, thermoplastics having a 40D-80Dshore durometer rating, such as nylon or polypropylene, and preferablyhaving a thickness between 0.005 and 0.015 inches.

[0035] The combination of the flexible, non-compliant surface overlayand the underlying compliant cushion provides for an insert that hasadvantages of both conventional rigid and atraumatic clamps. Thenon-compliant overlay provides for an engaging surface having the look,feel and clamping characteristics of a traditional rigid clamp, such asa hard metal clamp. However, the underlying compliant cushion willdeform upon application of a clamping load, which in turn also allowsthe overlay to flex in response to the load. The result is that theinsert as a whole deflects to accommodate a clamped vessel. Thisdeflection allows for a more atraumatic method of clamping a vesselwhile at the same time providing for gripping characteristics previouslyassociated only with rigid metal clamps. This deflecting action isillustrated in FIG. 4, which shows vessel V being engaged by clamp jawscontaining inserts 10.

[0036] FIGS. 5A-7B depict inserts according to a second embodiment ofthe invention. Insert 20 a of FIGS. 5A, 6 and 7A includes compliantcushion 24 and surface overlay 26. The cushion is secured to flexibleelongate attachment member 22 as described above. Surface overlay 26includes a series of notches 28 and 29 that are located along the sidesof the overlay. The addition of these notches does not diminish theadvantages of the cushion and overlay combination as previouslydescribed, but does operate to provide for increased flexibility of theoverlay. The increased flexibility is exhibited not only laterally, butalso, e.g., in directions perpendicular to the overlay surface, as wellas axial to the insert. This increased flexibility allows for anincreased ability to bend and twist the insert. This increasedflexibility of the overlay, together with the flexible nature ofattachment member 22, allows the insert to be more easily installed ontocurved jaws of varying configurations. Insert 20 b of FIGS. 5B and 7Bexhibits similar characteristics, with the exception that attachmentmember 22′ is integrally formed with cushion 24. This increasedflexibility of these inserts is illustrated in FIG. 5C which showsinsert 20 c in a flexed position. The flexibility of insert 20 c isfurther improved by the addition of notches 28′ provided in the cushionitself, which correspond to notches 28 in the surface overlay.

[0037] The clamping or engaging surface of the surface overlay of theinvention can be relatively smooth, as shown, for example, with surfaceoverlay 16. Alternatively, surface overlays according to the inventioncan be textured with surface irregularities, for example, repeating orrandom patterns of serrations, bumps, protrusions or other surfaceirregularities known in the art, in order to provide additional tractionwith a clamped vessel or engaged tissue. Other methods of providing asurface overlay textured with surface irregularities are alsocontemplated, including roughening the surface of the overlay, such asby scoring the surface.

[0038] FIGS. 8-10 depict a third embodiment of the invention having asurface overlay with a tractive surface. Insert 40 includes compliantcushion 44 and surface overlay 46. Overlay 46 is formed of a thin metal,preferably stainless steel, that has been perforated. Each perforation48 creates a surface irregularity that can increase the traction of theoverlay on a clamped vessel or tissue. The perforations can be formed ina variety of ways, including punching or stamping a smooth sheet ofmetal to form the perforations. In such cases, the resulting punchedholes will typically have roughened and irregular edges 49 extendingupward from the surface in the direction of the punching action, as isdepicted in FIG. 11. Such roughened and irregular hole edges provide foradditional traction with an engaged vessel or tissue. The hole edges maybe rounded off or otherwise smoothed to achieve the desired grippingsurface without being overly sharp.

[0039] FIGS. 12-14 depicts a fourth embodiment of the invention, alsohaving a surface overlay with a tractive surface having surfaceirregularities. In this embodiment, insert 60 includes cushion 64 andsurface overlay 66. Overlay 66 itself includes columns 68 extendingupward from the overlay, again for providing additional traction betweenthe insert and a clamped vessel or tissue. The columns extend from theoverlay in a direction generally perpendicular to the cushion surface.As illustrated, columns 68 are arranged in two parallel rows, with thecolumns within each row spaced uniformly, but it will be understood thatthe invention also contemplates other arrangements of columns, such asopposing, angled or random configurations. Likewise the columns may beof uniform cross-section as shown, or the column cross-sections mayvary, providing for a sharper, more pointed protrusive surface.

[0040] Inserts according to the present invention can be assembled inways known in the art. For ease of manufacture, where the compliantcushion is formed of, for example, an elastomeric thermoplastic, and theattachment member is formed of a separate material, it is desirable toemploy a process where the attachment member is first provided, and thenthe compliant cushion is overmolded onto the attachment member. Thesurface overlay can then be secured onto the cushion surface by avariety of means. If the overlay is also a thermoplastic, the overlaycan be subsequently overmolded onto the formed cushion. Alternatively,the overlay can be secured to the cushion surface by other means, suchas adhesive bonding or the like. Adhesive bonding is generally moreappropriate, for example, where the overlay is a metal. Other methods ofassembling the insert according to the invention will be readilyapparent to those skilled in the art.

[0041] It is to be appreciated that the invention contemplates insertshaving any combination of surface overlays and compliant cushions, asdescribed above. Further, any of the surface overlays and/or thecushions themselves can be provided with notches to increase flexibilityof the inserts. Also, any of the surface overlay and cushioncombinations can be mounted on or formed onto any of the attachingstructures described. Although only certain embodiments have beenillustrated and described, those having ordinary skill in the art willunderstand that the invention is not intended to be limited to thespecifics of any of these embodiments, but rather is defined by theaccompanying claims.

We claim
 1. An insert for attachment to a jaw of a jaw-type occlusiondevice, comprising: an attaching structure for attaching the insert tothe jaw; a compliant cushion secured to the attaching structure andhaving a surface; and a flexible non-compliant surface overlay securedonto the cushion surface for engagement with a vessel or other bodytissue.
 2. The insert of claim 1 wherein the surface overlay entirelycovers the cushion surface.
 3. The insert of claim 1 wherein the surfaceoverlay includes a series of notches extending along sides of theoverlay to provide for increased [lateral] flexibility of the overlay.4. The insert of claim 1 wherein the overlay is formed of metal.
 5. Theinsert of claim 4 wherein the overlay is perforated.
 6. The insert ofclaim 5 wherein perforations in the metal are formed by punching holesthrough the metal.
 7. The insert of claim 1 wherein the overlay isformed of a thermoplastic.
 8. The insert of claim 1 wherein the overlayincludes surface irregularities.
 9. The insert of claim 1 wherein theoverlay further includes protrusions extending from the overlay forproviding increased traction with an engaged vessel or body tissue. 10.The insert of claim 11 wherein the protrusions further comprise aplurality of columns extending from the overlay in a direction generallyperpendicular to the cushion surface.
 11. An insert for attachment to ajaw of a jaw-type occlusion device, the jaw having a channel or cavityextending longitudinally therein, the insert comprising: a compliantcushion having a surface; a flexible elongate attachment member having asecuring portion configured to extend through the jaw channel or cavity;and a flexible non-complaint surface overlay secured onto the cushionsurface for engagement with a vessel or other body tissue.
 12. Theinsert of claim 11 wherein the surface overlay entirely covers thecushion surface.
 13. The insert of claim 11 wherein the surface overlayincludes a series of notches extending along sides of the overlay toprovide for increased flexibility of the overlay.
 14. The insert ofclaim 11 wherein the overlay is formed of metal.
 15. The insert of claim14 wherein the overlay is perforated.
 16. The insert of claim 15 whereinperforations in the metal are formed by punching holes through themetal.
 17. The insert of claim 11 wherein the overlay is formed of athermoplastic.
 18. The insert of claim 11 wherein the overlay includessurface irregularities.
 19. The insert of claim 11 wherein the overlayfurther includes protrusions extending from the overlay for providingincreased traction with an engaged vessel or body tissue.
 20. The insertof claim 19 wherein the protrusions further comprise a plurality ofcolumns extending from the overlay in a direction generallyperpendicular to the cushion surface.
 21. An insert for attachment to ajaw of a jaw-type occlusion device, comprising: an attaching structurefor attaching the insert to the jaw; a compliant cushion secured to theattaching structure and having a surface; and a flexible non-complaintsurface overlay secured onto the cushion surface for engagement with avessel or other body tissue, the overlay being formed of a metal thatextends over the entire cushion surface.
 22. The insert of claim 21wherein the metal is perforated.
 23. The insert of claim 21 wherein theoverlay includes surface irregularities.
 24. The insert of claim 21wherein the surface overlay further includes a series of notchesextending along sides of the overlay to provide for increasedflexibility of the overlay.
 25. An insert for attachment to a jaw of ajaw-type occlusion device, comprising: an attaching structure forattaching the insert to the jaw; a compliant cushion secured to theattaching structure and having a surface; and a flexible non-complaintsurface overlay secured onto the cushion surface for engagement with avessel or other body tissue, the overlay being formed of a thermoplasticand further including a plurality of protrusions extending from theoverlay in a direction generally perpendicular to the cushion surfacefor increased traction with an engaged vessel or body tissue.
 26. Theinsert of claim 25 wherein the surface overlay further includes a seriesof notches extending along sides of the overlay to provide for increasedflexibility of the overlay.
 27. An insert for attachment to a jaw of ajaw-type occlusion device, comprising: a compliant cushion having firstand second surfaces, the second surface being adapted for releasableattachment to the jaw; and a flexible non-compliant surface overlaysecured onto the first surface of the cushion, the overlay adapted forengagement with a vessel or other body tissue.
 28. The insert of claim27 wherein the surface overlay entirely covers the first surface of thecushion.
 29. The insert of claim 27 wherein the surface overlay includesa series of notches extending along sides of the overlay to provide forincreased flexibility of the overlay.
 30. The insert of claim 27 whereinthe overlay is formed of metal.
 31. The insert of claim 30 wherein theoverlay is perforated.
 32. The insert of claim 31 wherein perforationsin the metal are formed by punching holes through the metal.
 33. Theinsert of claim 27 wherein the overlay is formed of a thermoplastic. 34.The insert of claim 27 wherein the overlay includes surfaceirregularities.
 35. The insert of claim 27 wherein the overlay furtherincludes protrusions extending from the overlay for providing increasedtraction with an engaged vessel or body tissue.
 36. The insert of claim35 wherein the protrusions further comprise a plurality of columnsextending from the overlay in a direction generally perpendicular to thecushion surface.